There are many methods to measure thermal conductivity of solid, but not many of them can be directly applied to ice measurements. In this paper, considering the problems related to sub-zero low temperature environment, and based on the steady-state method and Fourier law of thermal conductivity, it is attempted to design and enhance same concerned details by independent constructing the experiment equipment. The relationships between thermal conductivity and the ambient temperature, the impurity concentration (salt content) and the ratio of diameter to thickness of ice are studied. The result shows that when the ratio of diameter to thickness of ice is 12, the thermal conductivity tends to a best value of 2.25 w/m·K and the best ambient temperature is -10 ℃. When comparing with that of pure water ice, the thermal conductivity of salt water ice decreases significantly, and its value decreases gradually and becomes stable with the increase of salt content.